Planar end fire antenna for wideband low form factor applications

ABSTRACT

An end-fire antenna for wideband low form factor applications includes a first metal layer, a second metal layer, and a dielectric layer disposed between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND Field

Embodiments of the invention relate to electronic systems, and inparticular, to radio frequency (RF) electronics.

Description of the Related Art

Radio communication above 20 GHz is primarily line of sightcommunication. End fire antennae are used to provide end fire patternsfor end to end link between electronic devices, for example in filetransfer systems (e.g., downloading from a fixed terminal to a mobileterminal, or mobile-to-mobile communications). Additionally, a goodend-fire pattern for 60 GHz ISM band is needed where switching betweendifferent patterns to find the best Signal-to-Noise (SNR) ratio.

Two types of end fire antenna designs are currently used, both of whichhave various drawbacks discussed below. Printed antennae (e.g., Yagi,RPMA, UWB hexagonal, etc.) are one type of end fire antennae. However,printed antennae suffer from poor bandwidth in some designs, low gainand sensitivity to parallel conductive planes. Aperture antennae areanother type of end fire antennae. However, existing aperture antennaeresult in a tradeoff between effective bandwidth and size of thepackage. As the height of the package is decreased, the effectivebandwidth is also reduced. Further, existing technology does not allowfor a low form factor aperture antenna, and existing aperture antennashave very complex structures.

In existing end fire antennae, an increase in gain of the antennarequires an increase in size (e.g., thickness) of the antenna, making itdifficult to achieve high gain antennae in low form factor applications.Alternatively, a reduction in the thickness of the antenna packageresults in a reduction in the bandwidth and the gain. Additionally, asthe thickness of the package is reduced, the width (longer dimension) ofthe aperture in an aperture antenna needs to be increased to achievegood directivity, where the directivity is proportional to the aperturearea. However, an increase in the width of the aperture results in areduction in impedance, and can lead to the introduction of Ten0 modeswhich kill the gain across the bandwidth. The smallest thicknessreported in an aperture end-fire antenna, with 57-64 GHz bandwidth is 1mm, an array of 1×2, and overall size of 14.4 mm×14.4 mm×1 mm, giving a6 dBi gain.

SUMMARY

Accordingly, there is a need for an end-fire antenna, especially a 60GHz mobile antenna, that is able to meet height limitations and fit in apackage in low form factor applications, is isolated from surroundingenvironment, and provides a wide bandwidth and high gain.

In accordance with one aspect, a wireless mobile device is provided. Thewireless mobile device comprises an end-fire antenna defined by adielectric layer disposed between a pair of metal layers and an opencavity formed in the dielectric layer that is filled with air, thecavity defined by a pair of sidewalls that extend from an aperture ofthe cavity to a rear wall of the cavity, a depth of the cavity definedbetween the aperture and the rear wall.

In accordance with another aspect, an end-fire antenna is provided. Theend-fire antenna comprises a first metal layer, a second metal layer,and a dielectric layer disposed between the first and second metallayers. An open cavity is formed in the dielectric layer that is filledwith air, the cavity defined by a pair of sidewalls that extend from anaperture of the cavity to a rear wall of the cavity, a depth of thecavity defined between the aperture and the rear wall.

In accordance with another aspect, a radiofrequency module is provided,comprising an end-fire antenna defined by a dielectric layer disposedbetween a pair of metal layers and an open cavity formed in thedielectric layer that is filled with air, the cavity defined by a pairof sidewalls that extend from an aperture of the cavity to a rear wallof the cavity, a depth of the cavity defined between the aperture andthe rear wall.

In accordance with another aspect, a method of making an end-fireantenna is provided. The method comprises forming a first metal layer.The method also comprises forming dielectric layer in contact with thefirst metal layer. The method also comprises forming an open cavity inthe dielectric layer that is filled with air, the cavity defined by apair of sidewalls that extend from an aperture of the cavity to a rearwall of the cavity, a depth of the cavity defined between the apertureand the rear wall. The method also comprises forming a second metallayer in contact with an opposite side of the dielectric layer than thefirst metal layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of one example of a wireless devicethat can include one or more antenna switch modules.

FIG. 2 is a schematic block diagram of another example of a wirelessdevice that can include one or more antenna switch modules.

FIG. 3 is a schematic perspective view of one embodiment of an end fireaperture antenna.

FIG. 4 is a schematic perspective view of one embodiment of an end fireaperture antenna.

FIG. 5 is a schematic planar view of the end figure aperture antenna ofFIG. 3 .

FIG. 6 is a schematic perspective view of one embodiment of an end fireaperture antenna connected to a printed circuit board (shown without acavity).

FIG. 7 is a plot of gain versus frequency performance for an end firecavity aperture substrate integrated waveguide (SIW) antenna compared toa filled aperture antenna.

FIG. 8 is a plot of antenna return loss versus frequency performance foran end fire cavity aperture substrate integrated waveguide (SIW) antennacompared to a filled aperture antenna.

FIG. 9 is a plot showing sensitivity to cavity dimensions for an endfire cavity aperture substrate integrated waveguide (SIW) antenna.

FIG. 10A is a plot of radiation efficiency versus frequency for an endfire cavity aperture antenna compared with a filled aperture antenna.

FIG. 10B is a plot of radiation efficiency versus frequency for an endfire cavity aperture antenna over a wider bandwidth than FIG. 10A.

FIG. 11 shows an illustration of the mode suppression provided by an endfire cavity aperture antenna.

FIG. 12 shows a schematic perspective view of an array of antennas.

FIG. 13 shows a block diagram of a chip incorporating the array ofantennas.

FIG. 14A is a schematic diagram of one example of a downlink channelusing multi-input and multi-output (MIMO) communications.

FIG. 14B is schematic diagram of one example of an uplink channel usingMIMO communications.

FIG. 15 is a schematic diagram of one example of a communication systemthat operates with beamforming.

FIG. 16 is a schematic diagram of one embodiment of a mobile device.

FIG. 17 shows a schematic cross-sectional view of a semiconductor deviceincorporating multiple antennae.

FIG. 18 shows a block diagram of a radio frequency module including thesemiconductor device of FIG. 17 .

DETAILED DESCRIPTION

The headings provided herein, if any, are for convenience only and donot necessarily affect the scope or meaning of the claimed invention.

Overview of Examples of Wireless Devices that can Include Antenna SwitchModules

FIG. 1 is a schematic block diagram of one example of a wireless ormobile device 11 that can include one or more antenna switch modules.The wireless device 11 can include antenna switch modules implementingone or more features of the present disclosure.

Antenna switch modules can be used within the wireless or a mobiledevice 11 implementing a 5G telecommunication standard that may utilize30 GHz and 60-70 GHz frequency bands. Additionally, the 3G, 4G, LTE, orAdvanced LTE telecommunication standards can be used with the antennaswitch modules in the wireless or mobile device 11, as described herein.

The example wireless device 11 depicted in FIG. 1 can represent amulti-band and/or multi-mode device such as a multi-band/multi-modemobile phone. By way of examples, Global System for Mobile (GSM)communication standard is a mode of digital cellular communication thatis utilized in many parts of the world. GSM mode mobile phones canoperate at one or more of four frequency bands: 850 MHz (approximately824-849 MHz for Tx, 869-894 MHz for Rx), 900 MHz (approximately 880-915MHz for Tx, 925-960 MHz for Rx), 1800 MHz (approximately 1710-1785 MHzfor Tx, 1805-1880 MHz for Rx), and 1900 MHz (approximately 1850-1910 MHzfor Tx, 1930-1990 MHz for Rx). Variations and/or regional/nationalimplementations of the GSM bands are also utilized in different parts ofthe world.

Code division multiple access (CDMA) is another standard that can beimplemented in mobile phone devices. In certain implementations, CDMAdevices can operate in one or more of 800 MHz, 900 MHz, 1800 MHz and1900 MHz bands, while certain W-CDMA and Long Term Evolution (LTE)devices can operate over, for example, about 22 radio frequency spectrumbands.

In certain embodiments, the wireless device 11 can include an antennaswitch module 12, a transceiver 13, an antenna 14, power amplifiers 17,a control component 18, a computer readable medium 19, a processor 20,and a battery 21.

The transceiver 13 can generate RF signals for transmission via theantenna 14. Furthermore, the transceiver 13 can receive incoming RFsignals from the antenna 14. It will be understood that variousfunctionalities associated with transmitting and receiving of RF signalscan be achieved by one or more components that are collectivelyrepresented in FIG. 1 as the transceiver 13. For example, a singlecomponent can be configured to provide both transmitting and receivingfunctionalities. In another example, transmitting and receivingfunctionalities can be provided by separate components.

In FIG. 1 , one or more output signals from the transceiver 13 aredepicted as being provided to the antenna 14 via one or moretransmission paths 15. In the example shown, different transmissionpaths 15 can represent output paths associated with different bandsand/or different power outputs. For instance, the two different pathsshown can represent paths associated with different power outputs (e.g.,low power output and high power output), and/or paths associated withdifferent bands. The transmit paths 15 can include one or more poweramplifiers 17 to aid in boosting a RF signal having a relatively lowpower to a higher power suitable for transmission. Although FIG. 1illustrates a configuration using two transmission paths 15, thewireless device 11 can be adapted to include more or fewer transmissionpaths 15.

In FIG. 1 , one or more detected signals from the antenna 14 aredepicted as being provided to the transceiver 13 via one or morereceiving paths 16. In the example shown, different receiving paths 16can represent paths associated with different bands. For example, thefour example paths 16 shown can represent quad-band capability that somewireless devices are provided with. Although FIG. 1 illustrates aconfiguration using four receiving paths 16, the wireless device 11 canbe adapted to include more or fewer receiving paths 16.

To facilitate switching between receive and/or transmit paths, theantenna switch module 12 can be included and can be used electricallyconnect the antenna 14 to a selected transmit or receive path. Thus, theantenna switch module 12 can provide a number of switchingfunctionalities associated with an operation of the wireless device 11.The antenna switch module 12 can include a multi-throw switch configuredto provide functionalities associated with, for example, switchingbetween different bands, switching between different power modes,switching between transmission and receiving modes, or some combinationthereof. The antenna switch module 12 can also be configured to provideadditional functionality, including filtering and/or duplexing ofsignals.

FIG. 1 illustrates that in certain embodiments, the control component 18can be provided for controlling various control functionalitiesassociated with operations of the antenna switch module 12 and/or otheroperating component(s). For example, the control component 18 can aid inproviding control signals to the antenna switch module 12 so as toselect a particular transmit or receive path.

In certain embodiments, the processor 20 can be configured to facilitateimplementation of various processes on the wireless device 11. Theprocessor 20 can be a general purpose computer, special purposecomputer, or other programmable data processing apparatus. In certainimplementations, the wireless device 11 can include a computer-readablememory 19, which can include computer program instructions that may beprovided to and executed by the processor 20.

The battery 21 can be any suitable battery for use in the wirelessdevice 11, including, for example, a lithium-ion battery.

FIG. 2 is a schematic block diagram of another example of a wirelessdevice 30 that can include one or more antenna switch modules. Theillustrated wireless device 30 includes first to fifth antennas 14 a-14e, a power amplifier module 31, a front-end module 32, a diversityfront-end module 34, first to fifth antenna switch modules 40 a-40 e, amultimode transceiver 44, a Wi-Fi/Bluetooth module 46, and a FM/MobileTV module 48.

The multimode transceiver 44 is electrically coupled to the poweramplifier module 31, to the front-end module 32, and to the diversityfront-end module 34. The multimode transceiver 44 can be used togenerate and process RF signals using a variety of communicationstandards, including, for example, 5G, Global System for MobileCommunications (GSM), Code Division Multiple Access (CDMA), widebandCDMA (W-CDMA), Enhanced Data Rates for GSM Evolution (EDGE), and/orother proprietary and non-proprietary communications standards.

The power amplifier module 31 can include one or more power amplifiers,which be used to boost the power of RF signals having a relatively lowpower. Thereafter, the boosted RF signals can be used to drive the firstantenna 14 a. The power amplifier module 31 can include power amplifiersassociated with different power outputs (e.g., low power output and highpower output) and/or amplifications associated with different bands.

The front-end module 32 can include circuitry that can aid the multimodetransceiver 44 in transmitting and receiving RF signals. For example,the front-end module 32 can include one or more low noise amplifiers(LNAs) for amplifying signals received using the first antenna 14 a. Thefront-end module 32 can additionally and/or alternatively include filtercircuitry, input and output matching circuitry and/or power detectioncircuitry. In certain implementations, the front-end module 32 can alsoinclude one or more power amplifiers.

The first antenna switch module 40 a is electrically coupled to thefirst antenna 14 a, to the power amplifier module 31, and to thefront-end module 32. The first antenna switch module 40 a can be used toelectrically connect the first antenna 14 a to a desired transmit orreceive path. In certain embodiments described herein, the antennaswitch module 40 a can have a relatively small area, thereby improvingthe form factor of a mobile device used to communicate over a cellularor other network. The antenna switch module 40 a can also have a lowinsertion loss and high band-to-band isolation, which can improve thequality of signals transmitted or received. For example, the antennaswitch module can improve the quality of voice or data transmissionsmade using the first antenna 14 a and/or improve reception quality for agiven amount of power consumption.

In certain implementations, the diversity front-end module 34, thesecond antenna switch module 40 b, and the second or diversity antenna14 b can also be included. Using a diversity front-end module 34 and thesecond antenna 14 b can help improve the quality and/or reliability of awireless link by reducing line-of-sight losses and/or mitigating theimpacts of phase shifts, time delays and/or distortions associated withsignal interference of the first antenna 14 a. In some implementations,a plurality of diversity front-end modules, diversity antennas, andantenna switch modules can be provided to further improve diversity.

As illustrated in FIG. 2 , the second antenna switch module 40 b hasbeen used to select amongst a multitude of RF signal paths associatedwith the diversity antenna 14 b. In certain embodiments describedherein, the second antenna switch module 14 b can have a small area anda relatively low insertion loss and noise. Accordingly, the secondantenna switch module 14 b can help improve signal quality in thediversity signal path for a given power level, thereby reducing theprobability of a call drop-out or a lost connection. Furthermore, byproviding an antenna switch module with a smaller area, the form factorof the wireless device 30 can be reduced.

The wireless device 30 includes the Wi-Fi/Bluetooth module 46, which canbe used to generate and process received Wi-Fi and/or Bluetooth signals.For example, the Wi-Fi/Bluetooth module 46 can be used to connect to aBluetooth device, such as a wireless headset, and/or to communicate overthe Internet using a wireless access point or hotspot. To aid inselecting a desired Wi-Fi or Bluetooth signal path, the third antennaswitch module 14 c has been included. In certain embodiments describedherein, the antenna switch module 40 c can have a relatively small area,thereby improving the form factor of a mobile device used to communicateover the Internet and/or with a Bluetooth accessory. The antenna switchmodule 40 c can also have a low insertion loss and a high isolation,which can impact the quality of voice transmissions made or receivedusing a Bluetooth device and/or improve the quality of a Wi-Fi Internetconnection. For example, the antenna switch module 40 c can improveconnection strength and/or access range of the wireless device 30 to awireless access point for a given amount of power consumption.

The FM/Mobile TV module 48 can be included in the wireless device 30,and can be used to receive and/or transmit radio or television signals,such as FM signals and/or VHF signals. The FM/Mobile TV module 48 cancommunicate with the fourth and fifth antennas 14 d, 14 e using thefourth and fifth antenna switch modules 40 d, 40 e, respectively. Incertain embodiments, the antenna switch modules 40 d, 40 e can have arelatively small area, thereby improving the form factor of a mobiledevice having mobile TV or FM radio capabilities. Additionally, theantenna switch modules 40 d, 40 e can also have a low insertion loss andhigh isolation, which can lead to improved streaming of multimediacontent for a given amount of power consumption.

Although antenna switch modules have been illustrated and describedabove in the context of two examples of wireless devices, the antennaswitch modules described herein can be used in other wireless devicesand electronics.

End-Fire Aperture Antenna

FIGS. 3-5 show one embodiment of an antenna 100. In the illustratedembodiment, the antenna 100 is a generally planar end-fire antenna forwideband low form factor applications. The antenna 100 can include adielectric layer 102 disposed between metal plates 104, 106. The antenna100 has a cavity 108 (e.g., a single cavity) defined in the dielectriclayer 102. Advantageously, the cavity 108 is open (i.e., unfilled orfilled with air) and has a volume defined by side walls 116 a, 116 bthat extend from an opening 110 to a rear wall 108 c of the cavity 108(e.g., defining an air cavity). The cavity 108 is defined by a thickness112, a depth 114, and a width 111 of the opening 220. The end-fireantenna 100 can have tuning posts 118 to tune the center frequency, anda transition portion 120 to a micro-strip 122. The width 111 of theaperture or opening 110 can be tuned to achieve the desired directivity.The cavity 108 can be formed in the dielectric layer 102 using printedcircuit board (PCB) manufacturing processes.

In the illustrated embodiment, the cavity 108 is optionally a taperedcavity (e.g., the side walls 108 a, 108 b extend at an angle from theopening 110 to the rear wall 108 c, where the width of the opening 110along the X direction is greater than the width of the rear wall 108 c).In one embodiment, the taper angle α between the inclined side walls 108a, 108 b can be about 0-15 degrees. In one embodiment, the taper angle αcan be about 11 degrees. However, the taper angle α can have othersuitable values. In the illustrated embodiment, best shown in FIG. 5 ,the dimensions of the substrate integrated waveguide (SIW) end-fireantenna, excluding the transition 120, can be about 5.2 mm (width)×2.5mm (length)×0.4 mm (thickness or height). In other embodiments, theantenna 100 can have other suitable dimensions. For example, in otherembodiments the thickness or height of the antenna 100 can be reduced(e.g., to 200 microns, 300 microns) without having to vary the lengthand width of the antenna 100 or a drop in performance. The thickness 112can vary between about 100 microns and about 1 mm. In someimplementations, the thickness 112 can vary between 200 microns andabout 400 microns. However, the thickness 112 can have other suitablevalues that are greater or smaller than these. Accordingly, theembodiment disclosed herein for the antenna 100 including an air cavity108 allow for antenna dimensions suitable for low form factorapplications.

In another embodiment, the cavity 108 can optionally be rectangular(e.g., the side walls 108 a, 108 b extend generally parallel to eachother and the width of the opening 110 is generally equal to the widthof the rear wall 108 c). In still another embodiment, the cavity 108 canoptionally be diamond shaped (e.g., the side walls 108 a, 108 b betweenthe opening 110 and rear wall 108 c can be V-shaped to generally definea diamond shape). The cavity 108 can have other suitable shapes andstill achieve performance advantages described further below.

FIG. 6 shows a circuit board 130 to which the antenna 100 is connected.For clarity, the dielectric layer 102 and air cavity 108 are not shownin this figure. The side walls of the antenna 100 and posts are definedusing metal vias 124.

Advantageously, the cavity 108 (e.g. air cavity) increases the impedance(lower permittivity) of the waveguide, facilitating the matching of theantenna 100 to a wideband to achieve a wide bandwidth. Additionally, thecavity 108 reduced the effective permittivity and the cap, and increasesthe bandwidth. Further, the cavity 108 suppresses higher order modes(e.g., TE30 and above), as discussed further below, and thereforeimproves the radiation gain and directivity of the antenna 100. Thecut-off frequency of TE30 mode is three times the intended mode (TE10)and inversely proportional to the permittivity. Also, the air cavity 108is not very sensitive to asymmetry.

The antenna 100 can be used in mobile devices (e.g., formobile-to-mobile communications, or communication between a mobiledevice and a fixed terminal, such as a video download terminal), such asthe wireless device 11 in FIG. 1 and wireless device 30 in FIG. 2 . Inone embodiment, the antenna 100 can be implemented in smartphones.Advantageously, at 30 dB the antenna 100 can achieve a communicationrange of about 100 meters, whereas prior art antennas have acommunication range of 1-20 meters.

In use, the size of the cavity (e.g., the depth 114 and width 111 of theopening or aperture 110) is chosen to optimize the performance of theantenna 100 (e.g. to achieve the same gain as the thickness 112 of theantenna 100 is reduced, such as to meet a specific low form factorapplication). Advantageously, no adjustment in the overall size of theantenna 100 (e.g., length and width) is needed to achieve the same gainas the thickness 112 of the antenna 100 is decreased, unlike prior artaperture antennae. In the illustrated embodiments, as the thickness 112of the antenna 100 is reduced, the width 111 of the opening or aperture110 and/or depth 114 of the cavity 108 can be altered (e.g., increased)to achieve the same gain, without altering the overall dimensions(length, width) of the antenna 100. Accordingly, the antenna 100 doesnot suffer from the tradeoff between size and gain that occurs in priorart antennae (e.g., prior art aperture antennae) when need to reduce thethickness of the antenna.

FIGS. 7-10B illustrate the performance of one embodiment of an end-fireaperture antenna, in accordance with the features described in thisdisclosure, as compared with an end-fire filled aperture (e.g., withoutan air cavity). As discussed below, the performance of the end-fireaperture antenna is superior to that of the filled aperture antenna.With respect to FIGS. 7-8 and 10A, the performance of an end-fireaperture antenna (e.g., with an air cavity 108), similar to the antenna100 illustrated in FIGS. 3-5 was compared with the performance of anend-fire antennal without an aperture (e.g., filled or without acavity). The end-fire aperture antenna has a rectangular cavity 108 andcavity dimensions of 0.7 mm (depth 114)×1.6 mm (width 111)×0.4 mm(thickness 112). Both the end-fire aperture antenna and the end-firefilled aperture antenna used in the tests illustrated in FIGS. 7-10Bused HL972LD material with dielectric constant of 3.3, but the end-fireaperture antenna has an open air cavity, in accordance with theembodiments discussed herein, whereas the end-fire filled apertureantenna does not have a cavity formed in the dielectric layer.

FIG. 7 illustrates a comparison of gain vs. frequency for the end-fireaperture SIW antenna and the end-fire filled aperture SIW antenna. Asillustrated in the graph, the end-fire aperture antenna achieved agreater gain performance, achieving a maximum gain of about 9.5 dB or amaximum 4.7 dBi gain improvement in the band edges over the filledaperture antenna.

FIG. 8 illustrates a comparison of return loss vs. frequency for theend-fire aperture SIW antenna and the end-fire filled aperture SIWantenna. As illustrated in the graph, the end-fire aperture antennaachieved approximately a maximum 13 dB improvement in return loss. Theend-fire aperture antenna improved the return loss bandwidth more thanthree times in the industrial, scientific and medical (ISM) band, almosttripling the 10 dB bandwidth.

FIG. 9 illustrates the sensitivity of the end-fire aperture SIW antennato changes in the dimensions of the cavity 108. The cavity dimensionswere varied+/−50 microns in the width 111 of the opening or aperture110, and no significant changes in performance were observed.Accordingly, the performance of the end-fire aperture SIW antenna designdisclosed herein is not overly sensitive to changes in the size andalignment changes of the cavity 108.

FIG. 10A illustrates a comparison of radiation efficiency vs. frequencyfor the end-fire aperture SIW antenna and the end-fire filled apertureSIW antenna. As illustrated in the graph, the end-fire aperture antennaachieved greater radiation efficiency than the filled aperture antenna.FIG. 10B shows the radiation efficiency over a wider bandwidth. Theend-fire aperture antenna achieved more than 80% radiation efficiencybetween 58-70 GHz, and the radiation efficiency increased by almost 10%within the ISM band edge at 64 GHz relative to the filled apertureantenna.

FIG. 11 illustrates the mode suppression achieved by the cavity 108 ofthe antenna 100. The dominant propagation mode is TE10, but due to thewidening of the aperture to achieve the desired directivity, the TE30mode is introduced, which will reduce radiation efficiency. However,adding the cavity (e.g., air cavity 108) increases the cut-off frequencyof the TE30 mode, thereby eliminating the undesired mode so that TE10 isthe dominant mode.

FIG. 12 shows one embodiment of an antenna structure 150 that canincorporate multiple antennae, such as the end-fire antennas 100, in anarray. In the illustrated embodiment, the antenna structure 150 is a 2×2array having antennas 100A, 100B, 100C and 100D.

FIG. 13 shows a block diagram of an integrated circuit or chip 170 thatdrives the antenna structure 150, in the illustrated embodiment a 2×2array having antennas 100A, 100B, 100C and 100D. One of more of theantennas 100A-100D can optionally be end-fire antennas, such as theantenna 100 described above. Each of the antennas 100A-100D in the chip170 can communicate via a transmit path 172 that includes a switch(SPDT), power amplifier (PA), and variable gain amplifier (VGA) alongwith other componentry. The antennas 100A-100D can also communicate viaa receive path 174 that includes the switch (SPDT), a low noiseamplifier (LNA), and variable gain amplifier (VGA) along with othercomponentry in the chip 170.

Though FIGS. 12-13 show a 2×2 antenna array, one of skill in the artwill recognize that the antenna structure 150 can have an array of anynumber of antennas. Such antenna arrays can be used in multi-input andmulti-output (MIMO) communications, such as in massive MIMO systems (orlarge scale antenna systems), which can include a very large number ofantennas (e.g., hundreds or thousands), and which can be used in handsetor 5G technology (also referred to as 5G new radio (NR)).

Preliminary specifications for 5G NR support a variety of features, suchas communications over millimeter wave spectrum, beam formingcapability, high spectral efficiency waveforms, low latencycommunications, multiple radio numerology, and/or non-orthogonalmultiple access (NOMA). Although such RF functionalities offerflexibility to networks and enhance user data rates, supporting suchfeatures can pose a number of technical challenges. The antennastructure disclosed herein is applicable to a wide variety ofcommunication systems, including, but not limited to, communicationsystems using advanced cellular technologies, such as LTE-Advanced,LTE-Advanced Pro, and/or 5G NR.

FIG. 14A is a schematic diagram of one example of a downlink channelusing multi-input and multi-output (MIMO) communications. FIG. 14B isschematic diagram of one example of an uplink channel using MIMOcommunications.

MIMO communications use multiple antennas for simultaneouslycommunicating multiple data streams over common frequency spectrum. Incertain implementations, the data streams operate with differentreference signals to enhance data reception at the receiver. MIMOcommunications benefit from higher signal-to-noise ratio (SNR), improvedcoding, and/or reduced signal interference due to spatial multiplexingdifferences of the radio environment.

MIMO order refers to a number of separate data streams sent or received.For instance, MIMO order for downlink communications can be described bya number of transmit antennas of a base station and a number of receiveantennas for user devices or user equipment (UE), such as a mobiledevice. For example, two-by-two (2×2) DL MIMO refers to MIMO downlinkcommunications using two base station antennas and two UE antennas.Additionally, four-by-four (4×4) DL MIMO refers to MIMO downlinkcommunications using four base station antennas and four UE antennas.

In the example shown in FIG. 14A, downlink MIMO communications areprovided by transmitting using M antennas 183 a, 183 b, 183 c, . . . 183m of the base station 181 and receiving using N antennas 184 a, 184 b,184 c, . . . 184 n of the mobile device 182. Accordingly, FIG. 2Aillustrates an example of M×N DL MIMO.

Likewise, MIMO order for uplink communications can be described by anumber of transmit antennas of UE, such as a mobile device, and a numberof receive antennas of a base station. For example, 2×2 UL MIMO refersto MIMO uplink communications using two UE antennas and two base stationantennas. Additionally, 4×4 UL MIMO refers to MIMO uplink communicationsusing four UE antennas and four base station antennas.

In the example shown in FIG. 14B, uplink MIMO communications areprovided by transmitting using N antennas 184 a, 184 b, 184 c, . . . 184n of the mobile device 182 and receiving using M antennas 183 a, 183 b,183 c, . . . 183 m of the base station 41. Accordingly, FIG. 14 Billustrates an example of N×M UL MIMO.

By increasing the level or order of MIMO, bandwidth of an uplink channeland/or a downlink channel can be increased.

MIMO communications are applicable to communication links of a varietyof types, such as FDD communication links and TDD communication links.

FIG. 15 is a schematic diagram of one example of a communication system190 that operates with beamforming. The communication system 190includes a transceiver 195, signal conditioning circuits 194 a 1, 194 a2 . . . 194 an, 194 b 1, 194 b 2 . . . 194 bn, 194 m 1, 194 m 2 . . .194 mn, and an antenna array 192 that includes antenna elements 193 a 1,193 a 2 . . . 193 an, 193 b 1, 193 b 2 . . . 193 bn, 193 m 1, 193 m 2 .. . 193 mn.

Communications systems that communicate using millimeter wave carriers(for instance, 30 GHz to 300 GHz), centimeter wave carriers (forinstance, 3 GHz to 30 GHz), and/or other frequency carriers can employan antenna array to provide beam formation and directivity fortransmission and/or reception of signals.

For example, in the illustrated embodiment, the communication system 190includes an array 192 of m×n antenna elements, which are each controlledby a separate signal conditioning circuit, in this embodiment. The array192 can be similar to the array 150 described above in FIGS. 12-13 . Asindicated by the ellipses, the communication system 190 can beimplemented with any suitable number of antenna elements and signalconditioning circuits.

With respect to signal transmission, the signal conditioning circuitscan provide transmit signals to the antenna array 192 such that signalsradiated from the antenna elements combine using constructive anddestructive interference to generate an aggregate transmit signalexhibiting beam-like qualities with more signal strength propagating ina given direction away from the antenna array 192.

In the context of signal reception, the signal conditioning circuitsprocess the received signals (for instance, by separately controllingreceived signal phases) such that more signal energy is received whenthe signal is arriving at the antenna array 192 from a particulardirection. Accordingly, the communication system 190 also providesdirectivity for reception of signals.

The relative concentration of signal energy into a transmit beam or areceive beam can be enhanced by increasing the size of the array. Forexample, with more signal energy focused into a transmit beam, thesignal is able to propagate for a longer range while providingsufficient signal level for RF communications. For instance, a signalwith a large proportion of signal energy focused into the transmit beamcan exhibit high effective isotropic radiated power (EIRP).

In the illustrated embodiment, the transceiver 195 provides transmitsignals to the signal conditioning circuits and processes signalsreceived from the signal conditioning circuits. As shown in FIG. 15 ,the transceiver 195 generates control signals for the signalconditioning circuits. The control signals can be used for a variety offunctions, such as controlling the phase of transmitted or receivedsignals to control beam forming.

FIG. 16 is a schematic diagram of one example of a mobile device 200.The mobile device 200 includes a baseband system 201, a transceiver 202,a front end system 203, antennas 204, a power management system 205, amemory 206, a user interface 207, and a battery 208.

The mobile device 200 can be used communicate using a wide variety ofcommunications technologies, including, but not limited to, 2G, 3G, 4G(including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G NR, WLAN (forinstance, Wi-Fi), WPAN (for instance, Bluetooth and ZigBee), WMAN (forinstance, WiMax), and/or GPS technologies.

The transceiver 202 generates RF signals for transmission and processesincoming RF signals received from the antennas 204. It will beunderstood that various functionalities associated with the transmissionand receiving of RF signals can be achieved by one or more componentsthat are collectively represented in FIG. 16 as the transceiver 202. Inone example, separate components (for instance, separate circuits ordies) can be provided for handling certain types of RF signals.

The front end system 203 aids is conditioning signals transmitted toand/or received from the antennas 204. In the illustrated embodiment,the front end system 203 includes power amplifiers (PAs) 211, low noiseamplifiers (LNAs) 212, filters 213, switches 214, and duplexers 215.However, other implementations are possible.

For example, the front end system 203 can provide a number offunctionalities, including, but not limited to, amplifying signals fortransmission, amplifying received signals, filtering signals, switchingbetween different bands, switching between different power modes,switching between transmission and receiving modes, duplexing ofsignals, multiplexing of signals (for instance, diplexing ortriplexing), or some combination thereof.

In certain implementations, the mobile device 200 supports carrieraggregation, thereby providing flexibility to increase peak data rates.Carrier aggregation can be used for both Frequency Division Duplexing(FDD) and Time Division Duplexing (TDD), and may be used to aggregate aplurality of carriers or channels. Carrier aggregation includescontiguous aggregation, in which contiguous carriers within the sameoperating frequency band are aggregated. Carrier aggregation can also benon-contiguous, and can include carriers separated in frequency within acommon band or in different bands.

The antennas 204 can include antennas used for a wide variety of typesof communications. For example, the antennas 204 can include antennasfor transmitting and/or receiving signals associated with a wide varietyof frequencies and communications standards. The antennas 204 can be anyantennas described herein, such as the end-fire antennas 100, 325,planar antennas 370, or a combination of antenna types.

In certain implementations, the antennas 204 support MIMO communicationsand/or switched diversity communications. For example, MIMOcommunications use multiple antennas for communicating multiple datastreams over a single radio frequency channel. MIMO communicationsbenefit from higher signal to noise ratio, improved coding, and/orreduced signal interference due to spatial multiplexing differences ofthe radio environment. Switched diversity refers to communications inwhich a particular antenna is selected for operation at a particulartime. For example, a switch can be used to select a particular antennafrom a group of antennas based on a variety of factors, such as anobserved bit error rate and/or a signal strength indicator.

The mobile device 200 can operate with beamforming in certainimplementations. For example, the front end system 203 can include phaseshifters having variable phase controlled by the transceiver 202.Additionally, the phase shifters are controlled to provide beamformation and directivity for transmission and/or reception of signalsusing the antennas 204. For example, in the context of signaltransmission, the phases of the transmit signals provided to theantennas 204 are controlled such that radiated signals from the antennas204 combine using constructive and destructive interference to generatean aggregate transmit signal exhibiting beam-like qualities with moresignal strength propagating in a given direction. In the context ofsignal reception, the phases are controlled such that more signal energyis received when the signal is arriving to the antennas 204 from aparticular direction. In certain implementations, the antennas 204include one or more arrays of antenna elements to enhance beamforming.

The baseband system 201 is coupled to the user interface 207 tofacilitate processing of various user input and output (I/O), such asvoice and data. The baseband system 201 provides the transceiver 202with digital representations of transmit signals, which the transceiver202 processes to generate RF signals for transmission. The basebandsystem 201 also processes digital representations of received signalsprovided by the transceiver 202. As shown in FIG. 16 , the basebandsystem 201 is coupled to the memory 206 of facilitate operation of themobile device 200.

The memory 206 can be used for a wide variety of purposes, such asstoring data and/or instructions to facilitate the operation of themobile device 200 and/or to provide storage of user information.

The power management system 205 provides a number of power managementfunctions of the mobile device 200. In certain implementations, thepower management system 205 includes a PA supply control circuit thatcontrols the supply voltages of the power amplifiers 211. For example,the power management system 205 can be configured to change the supplyvoltage(s) provided to one or more of the power amplifiers 211 toimprove efficiency, such as power added efficiency (PAE).

As shown in FIG. 16 , the power management system 205 receives a batteryvoltage from the battery 208. The battery 208 can be any suitablebattery for use in the mobile device 200, including, for example, alithium-ion battery.

Antenna Structure

FIG. 17 shows one embodiment of a semiconductor device 300. In theillustrated embodiment, the semiconductor device 300 is a flip chip die300 with multiple layers L1-L5 (e.g., of substrate material) connectedby vias. A top layer 310 and a bottom layer 320 can include a soldermask. The die 300 can optionally include an antenna 325 (similar to theend-fire antenna 100 described above). The antenna 325 can include adielectric layer 330 between metal layers 340, 350, and a cavity 360(e.g., unfilled or filled with air) defined in the dielectric layer 330.The cavity 360 can be formed in the same manner as the cavity 108described above. The antenna 325 can connected to a ground plane by vias365. The antenna 325 can function in a similar manner as the antenna 100described above, and can radiate laterally (e.g., to the left in FIG. 17).

With continued reference to FIG. 17 , the die 300 can also optionallyinclude a planar antenna 370 with a flat metal layer 380 that is spacedfrom the metal later 340 and connected to a ground plane by vias 385. Inone embodiment, the planar antenna 370 can be a patch antenna. Inanother embodiment, the planar antenna 370 can be any planar antenna(e.g., with broadside radiation pattern, such as loop, planar inverted Fantenna, etc.). The planar antenna 370 can radiate upward (e.g., in theupward direction as in FIG. 17 ). In the illustrated embodiment, themetal layers 340, 350 can be spaced apart by approximately 400 μm, themetal later 380 can be spaced from the metal later 340 by approximately300 μm, and the die 300 can have a thickness T of approximately 800 μm.However, in other embodiments, other suitable values can be used.Advantageously, by incorporating the planar antenna 370 and the end-fireantenna 325, the die 300 allows for diversity of direction and antennacoverage in the die 300 (e.g., in a transceiver chip) to cover a greaterarea as compared with a die that only has one, but not both, of theplanar antenna 370 and end fire antenna 325. In other embodiments, thedie 300 can exclude the antenna 325 and simply have the planar antenna370.

The semiconductor device 300 can optionally be implemented in a radiofrequency (RF) device or module 400, as shown in FIG. 18 . The radiofrequency device 400 can have a printed circuit board 410 to which thesemiconductor device or die 300 can connect. The semiconductor device ordie 300 can include an end-fire antenna, such as the antenna 325, 100, aplanar antenna, such as the planar antenna 370, and additionalcomponentry. For example, the semiconductor device 300 can have anantenna switch module 390 that can communicate with the end-fire antennaand planar antenna, an can also optionally have a power amplifier (PA)392 and low noise amplifier (LNA) 394 that can communicate with theantenna switch module 390. The radio frequency device 400 can be awireless device, a wire-based device, or some combination thereof.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms. Furthermore, various omissions, substitutions and changes in thesystems and methods described herein may be made without departing fromthe spirit of the disclosure. For example, one portion of one of theembodiments described herein can be substituted for another portion inanother embodiment described herein. The accompanying claims and theirequivalents are intended to cover such forms or modifications as wouldfall within the scope and spirit of the disclosure. Accordingly, thescope of the present inventions is defined only by reference to theappended claims.

Features, materials, characteristics, or groups described in conjunctionwith a particular aspect, embodiment, or example are to be understood tobe applicable to any other aspect, embodiment or example described inthis section or elsewhere in this specification unless incompatibletherewith. All of the features disclosed in this specification(including any accompanying claims, abstract and drawings), and/or allof the steps of any method or process so disclosed, may be combined inany combination, except combinations where at least some of suchfeatures and/or steps are mutually exclusive. The protection is notrestricted to the details of any foregoing embodiments. The protectionextends to any novel one, or any novel combination, of the featuresdisclosed in this specification (including any accompanying claims,abstract and drawings), or to any novel one, or any novel combination,of the steps of any method or process so disclosed.

Furthermore, certain features that are described in this disclosure inthe context of separate implementations can also be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation can also beimplemented in multiple implementations separately or in any suitablesubcombination. Moreover, although features may be described above asacting in certain combinations, one or more features from a claimedcombination can, in some cases, be excised from the combination, and thecombination may be claimed as a subcombination or variation of a subcombination.

Moreover, while operations may be depicted in the drawings or describedin the specification in a particular order, such operations need not beperformed in the particular order shown or in sequential order, or thatall operations be performed, to achieve desirable results. Otheroperations that are not depicted or described can be incorporated in theexample methods and processes. For example, one or more additionaloperations can be performed before, after, simultaneously, or betweenany of the described operations. Further, the operations may berearranged or reordered in other implementations. Those skilled in theart will appreciate that in some embodiments, the actual steps taken inthe processes illustrated and/or disclosed may differ from those shownin the figures. Depending on the embodiment, certain of the stepsdescribed above may be removed, others may be added. Furthermore, thefeatures and attributes of the specific embodiments disclosed above maybe combined in different ways to form additional embodiments, all ofwhich fall within the scope of the present disclosure. Also, theseparation of various system components in the implementations describedabove should not be understood as requiring such separation in allimplementations, and it should be understood that the describedcomponents and systems can generally be integrated together in a singleproduct or packaged into multiple products.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures are described herein. Not necessarily all such advantages maybe achieved in accordance with any particular embodiment. Thus, forexample, those skilled in the art will recognize that the disclosure maybe embodied or carried out in a manner that achieves one advantage or agroup of advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements, and/or steps areincluded or are to be performed in any particular embodiment.

Conjunctive language such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to convey that an item, term, etc. may beeither X, Y, or Z. Thus, such conjunctive language is not generallyintended to imply that certain embodiments require the presence of atleast one of X, at least one of Y, and at least one of Z.

Language of degree used herein, such as the terms “approximately,”“about,” “generally,” and “substantially” as used herein represent avalue, amount, or characteristic close to the stated value, amount, orcharacteristic that still performs a desired function or achieves adesired result. For example, the terms “approximately”, “about”,“generally,” and “substantially” may refer to an amount that is withinless than 10% of, within less than 5% of, within less than 1% of, withinless than 0.1% of, and within less than 0.01% of the stated amount. Asanother example, in certain embodiments, the terms “generally parallel”and “substantially parallel” refer to a value, amount, or characteristicthat departs from exactly parallel by less than or equal to 15 degrees,10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree.

The scope of the present disclosure is not intended to be limited by thespecific disclosures of preferred embodiments in this section orelsewhere in this specification, and may be defined by claims aspresented in this section or elsewhere in this specification or aspresented in the future. The language of the claims is to be interpretedbroadly based on the language employed in the claims and not limited tothe examples described in the present specification or during theprosecution of the application, which examples are to be construed asnon-exclusive.

What is claimed is:
 1. A radio frequency device comprising: a substrate;a power amplifier supported by the substrate and configured to amplify aradio frequency transmit signal; and a first antenna supported by thesubstrate and configured to transmit the radio frequency transmitsignal, the first antenna including a first metal layer, a second metallayer, a solid dielectric layer disposed between the first and secondmetal layers, antenna sidewalls extending between the first and secondmetal layers, and a cavity formed in the solid dielectric layer, thecavity positioned between the antenna sidewalls, and the cavity havingcavity sidewalls spaced from the antenna sidewalls and extending from anaperture of the cavity to a rear of the cavity.
 2. The radio frequencydevice of claim 1 further comprising a planar antenna formed in a thirdmetal layer that is spaced from the first metal layer by a seconddielectric layer.
 3. The radio frequency device of claim 2 wherein thecavity based first antenna and the planar antenna are arranged toradiate in generally orthogonal directions.
 4. The radio frequencydevice of claim 1 wherein the cavity is enclosed.
 5. The radio frequencydevice of claim 4 wherein the cavity is filled with air.
 6. The radiofrequency device of claim 4 wherein a top of the cavity is bounded bythe first metal layer, a bottom of the cavity is bounded by the secondmetal layer, and the cavity sidewalls and the rear and the aperture ofthe cavity are bounded by the solid dielectric layer.
 7. The radiofrequency device of claim 1 further comprising a second antennaintegrated together with the first antenna, the second antenna includinga cavity.
 8. The radio frequency device of claim 1 wherein the antennasidewalls include metal vias.
 9. A wireless mobile device comprising: afirst antenna, the first antenna including a first metal layer, a secondmetal layer, a solid dielectric layer disposed between the first andsecond metal layers, antenna sidewalls extending between the first andsecond metal layers, and an open cavity formed in the solid dielectriclayer, the cavity positioned between the antenna sidewalls, and thecavity having cavity sidewalls spaced from the antenna sidewalls andextending from an aperture of the cavity to a rear of the cavity. 10.The wireless mobile device of claim 9 further comprising a planarantenna formed in a third metal layer that is spaced from the firstmetal layer by a second dielectric layer.
 11. The wireless mobile deviceof claim 10 wherein the cavity based first antenna and the planarantenna are arranged to radiate in different directions.
 12. Thewireless mobile device of claim 9 wherein the cavity is enclosed. 13.The wireless mobile device of claim 12 wherein the cavity is filled withair.
 14. The wireless mobile device of claim 12 wherein a top of thecavity is bounded by the first metal layer, a bottom of the cavity isbounded by the second metal layer, and the cavity sidewalls and the rearand the aperture of the cavity are bounded by the solid dielectriclayer.
 15. The wireless mobile device of claim 9 wherein the antennasidewalls include metal vias.
 16. An antenna array comprising: an arrayof a plurality of antennas, each of the antennas including a first metallayer, a second metal layer, a solid dielectric layer disposed betweenthe first and second metal layers, antenna sidewalls extending betweenthe first and second metal layers, and a cavity formed in the soliddielectric layer, the cavity positioned between the antenna sidewalls,and the cavity having cavity sidewalls spaced from the antenna sidewallsand extending from an aperture of the cavity to a rear of the cavity.17. Then antenna array of claim 16 wherein the plurality of antennas arearranged in a single row.
 18. The antenna array of claim 16 wherein theplurality of antennas are arranged in a plurality of rows such that atleast one of the antennas is stacked on another of the antennas.
 19. Theantenna array of claim 16 wherein the antenna sidewalls are formed frommetal vias.